The present invention deals with vegetable fats and oils, particularly with olive oil. Fats and oils form a substantial part of the average human food consumption. Since fat consumption is associated with an increased risk of cardiovascular disorders, the nutritional value of different types of fat as well as methods for reducing the amount of fat in food compositions had been the object of extensive investigations. Presently not only the triglyceride part of fats is the subject of such investigations, but also the nature and the effects on health of fat attributes, the so-called minor components which are present in small amounts in non-refined natural fats. It has recently been found that the minor components which are denoted as anti-oxidants, including fat polyphenols, positively interfere with the body's cardiovascular system.
Traditionally, most natural fats are refined before they are used as an ingredient for the preparation of food. However, traditional fat refining is not discriminating to the nature of the fat ingredients and aims at the removal of all substances other than triglycerides, including minor components.
Oils and fats aimed for human consumption are subjected to a refining treatment. Only for a minor part of those the refining is limited to a simple water washing and decantation or centrifugation. Such so-called virgin oils, particularly virgin olive oils, are much appreciated for their rich taste.
Most fats and oils, however, are purified and deodorised by a refining treatment under, often, drastic conditions. Impure olive oil e.g., traditionally is deodorized at temperatures of 250.degree. C. or even more. Under such conditions also the oil's valuable minor components, including natural anti-oxidants, particularly the typical olive oil polyphenols are nearly fully stripped away.
WO 97/06697 teaches that food products can be fortified with anti-oxidants, including polyphenols. The patent particularly discloses the use of water soluble tea polyphenols.
Polyphenols present in olive oil are more or less fat soluble and have a chemical composition different from the water soluble polyphenols. They are presumed to play in the body an anti-oxidant role in specific tissues, possibly because of their fat solubility.
The introduction or re-introduction of polyphenols in refined vegetable oils, including olive oil, in a simple, natural and cheap way is the subject of the present invention.